The
CZ-1
(Chang Zheng) was derived from the DF-4*
missile (DF-3with upperstage) which was added a solid fuel third stage. The CZ-1
launcher was 28 m high for 77.4 tons at takeoff and could orbit a 0.300 tons
payload at 440 km with 70° inclination. It launched the two first Chinese satellites
from Juiquan in 1970 and 1971 after a failure in 1969.
* "The DF-4 would use the DF-3 as the first stage and carry a 2,200 kg payload;
it would have the same warhead as the DF-3 but with more heat-isulatoin material
for higher reentry speeds. Its second-stage engine would be outfitted with a fiberglass-reinforced
nozzle of large expansion ratio. R&D on the DF-4 started in March 1965. The first
succesful flight of a redesigned DF-4 was on January 30, 1970. The first-stage lift-off
thrust would be 104 tonnes and its second stage lengtened by 0.42 m in order to
contain an additional two tonnes of propellant. The missile range would be
about 4,500 km."
The CZ-1Dis developed
based on theDF-4A.It is
a larger
3-stage launch vehicle with an orbit-maneuver solid motor
(3-axis controlled by cold gas
N2 thruster system).
It is dedicated for launching small satellites into Low Earth Orbit (LEO) and Sun-synchronous
Orbit (SSO). The Launch Vehicle successfully conducted its first flight in Nov.
1997.

About the engines in the first and second stage
of the rocket nothing is published up to now.Meanwhile at first by Novosti Kosmonavtiki
sensational photos of the Chinese engine
YF-2published. It is now confirmed that four single engines
are combined with its own turbopumps. The shape of the chambers and the nozzles
are more similar to the smaller Scud-B engine than to the Nodong engine. The Nodong
engine has greater similarity to the Soviet four-chamber engine
Isayev S2.1150(Burya booster). In addition however clear differences
between all engines are to be determined. In any case, this engine YF-2 (4 x YF-1)
is a creation of Isayev's design bureau (codename 5D10). All the details
are typical. The second stage powered by asingle
YF-3 engine,which was a high-altitude version of the YF-1 (?).Due to high temperature in tests, the initial
use of titanium sheet for the nozzle was abandoned and hardened resin used finally.
This engine also is used for the second stage of DF-4 missile.All engines uses the fuel combination UDMH/AK-27S.

Around the year 1997 the engine was replaced by the gimbaled
YF-40 engine with the fuel combination
UDMH/N2O4. The new rocket is called CZ-2D, and also gets a new third
stage. It is an orbit-maneuver solid motor FG-36 with 3-axis controlled
by cold N2 gas thruster system).

Changzheng 1 (CZ-1)
Source: dragoninspace.com

The CZ-1 was China’s first space launch vehicle. The rocket was based on the
two-stage DF-4 liquid-propellant IRBM, added with a solid-rocket third-stage.
The CZ-1 only made two launches, sending China’s first artificial satellite
Dongfanghong 1 into the orbit on 24 April 1970, followed by the second satellite
Shijian 1 on 3 March 1971.
The development of the CZ-1 was originally assigned to the Eighth Academy,
with Wang Xi-ji being the chief designer. The programme was later reassigned
to the First Academy (now China Academy of Launch Vehicle Technology, CALT),
with Ren Xin-min being the chief designer.
Development
The CZ-1 development was initiated in July 1965 in response to the demand
for a rocket booster to launch China’s first satellite Dongfanghong 1 (Project
651). It was decided that the Shanghai Academy of Mechatronics (SAM) would
be tasked with the development of the civilian rocket Changzheng 1, so that
the First Academy could continue the development of the ballistic missiles.
The CZ-1 design team was led by Wang Xi-ji, the deputy chief of the SAM.
With no previous experience in developing large rocket, the design team decided
to base the space launch vehicle on the DF-4 liquid ICBM, which was under
development at the First Academy. In order to achieve enough velocity to escape
the Earth gravity, a solid rocket-powered third-stage would be added to the
two-stage DF-4. This design would enable the rocket to send 300kg payload
into 400km LEO inclined at 70°.
The Fourth Academy developed the GF-02 solid rocket motor with the ability
to ignite at high altitude. The solid rocket motor was tested onboard the
T-7A sounding rocket. Two launches were conducted in August 1968, both of
which were successful. The test results showed that the rocket motor could
be ignited at any altitude from less than 100km to 320km.
In November 1967, the National Defence Science & Technology Commission (NDSTC)
decided to combine the DF-4 and CZ-1 programmes. The CZ-1 development was
reassigned to the First Academy headed by Ren Xin-min. The First Academy was
asked to speed up the development of the DF-4/CZ-1, with the aim to launch
China’s first satellite in 1968.
The First Academy made some amendments to the original CZ-1 design. The modified
design had a launch weight of 81.5 tonnes and a launch thrust of 104 tonnes.
The rocket was 29.46m in length and 2.25m in diameter. The first- and second-stage
of the launch vehicle were completely identical to those of the DF-4. The
third-stage was fitted with its own flight control for the gliding stage of
the flight. The fuel mass was increased from 900kg to 1,800kg. The original
inertial guidance on the third-stage was replaced by a simpler spin-stabilisation.
Explosive charges were adopted for the separation of the second- and third-stage
and the jettison of the payload fairing to improve reliability. The third-stage
was also added with a primitive telemetry system.
The DF-4/CZ-1 development was interrupted by the political turmoil during
the Culture Revolution in the late 1960s. The missile was not ready for flight
test until 1969. The batch-01 produced in 1969 included 7 two-stage flight
test examples and 2 three-stage space launch vehicles.
Following two unsuccessful attempts in late 1969, the first depressed trajectory
flight test of the DF-4 was conducted from the Jiuquan Satellite Launch Centre
on 30 January 1970. The two stages of the missile separated and the second-stage
ignited successfully as scheduled, and the warhead hit the target spot with
high accuracy. The success of the test flight paved the way for the maiden
flight of the CZ-1 to send China's first satellite into space.

In 1969, the First Academy proposed an improved model CZ-1A, which featured
a newly-designed liquid-propellant, three-axis stabilised, fully-guided third-stage
to give greater payload capacity and orbit insertion accuracy. The launch
vehicle would be used to launch the Dengta 1 navigation satellite and the
Shijian 2 scientific satellite. However, the project did not go ahead.
Two further improved variants, designated CZ-1B and CZ-1C, were proposed in
the late 1970s, but neither had entered the engineering development stage.
In the 1990s, CALT introduced the CZ-1D as a small-life launch system for
the commercial space launch market. The launch vehicle featured redesigned
second- and third-stage for improved reliability and greater payload capacity
(800~1,000kg to 200km LEO, or 350kg to 900km SSO). It made a successful maiden
flight in November 1997, but hasn't flown since then.

Propulsion
The first- and second-stage of the CZ-1 were designed by the First Academy
based on the DF-4 IRBM, and were built by 211 Plant situated in south suburb
of Beijing. Both stages used a liquid bipropellant, with unsymmetrical dimethylhydrazine
(UDMH) as fuel and nitric acid (HNO3) as an oxidiser.
The first-stage of the rocket was powered by an YF-2 liquid rocket engine,
which consisted of four parallel YF-1 chamber motors.
The second-stage was powered by a single YF-3 liquid rocket engine, which
was a high-altitude version of the YF-1 (?) capable of working in a vacuum
environment. Development began in 1965 and completed in 1968.
The third-stage was powered by a GF-02 solid rocket motor developed by the
Fourth Academy in Inner Mongolia. Development began in April 1967 and the
motor was successfully tested in late 1969.Airframe
The airframe of the CZ-1 consisted of payload fairing, telemetry instrument
compartment, flight control instrument compartment, four propellant tanks,
two inter-stage sections, heat-resistant fuel tank bottoms and fuel/gas pipelines.
The CZ-1 adopted a “hot” inter-stage separation, where the adjacent stages
were separated by the impingement of the hot exhaust gas jet from the engine
of the ongoing stage. The engine of the second-stage ignited when the two
stages were still connected together, thus, eliminating the need for jettisoning
devices to provide the separation impulse and considerably reducing the none
control duration during the separation. A fibreglass heat insulation layer
is added on the top of the first-stage tank to prevent damage due to the high
pressure and hot stream of engine exhaust from the upper stage.
The addition of the third-stage increased the length-diameter ratio of the
CZ-1 to 13.27, which had weakened the rocket’s structural strength. To reduce
the rocket’s length as much as possible, the fuel and the oxidiser tanks were
combined into a single tank divided by a floor structure. The second-stage
motor was also direct mounted to the lower part of the propellant tank, so
that the tank formed part of the stage’s thrust and weight bearing load structure.
The two modifications had shortened the rocket’s overall length by 2m.Guidance
The CZ-1 used a cascade compensation inertial guidance system, similar to
that of the DF-4. As the rocket needed to fly powerlessly for 280 seconds
before the ignition of the third-stage engine, a flight control system was
added using pressurised nitrogen gas to maintain the course of its flight.
The third-stage of the launch vehicle was unguided, using spin-stabilisation
to maintain its flight course. It relied on a timing device to generate signals
for initialising the spin and satellite separation.

Changzheng 1D (CZ-1D)
Source: dragoninspace.com

The CZ-1D was introduced by CALT in the late 1990s as a small-lift launch
vehicle for the commercial space launch market. The launch vehicle was based
on a specially modified DF-4. The vehicle made its first successful flight
on 1 November 1997, but has never flown for a satellite launch mission.
The CZ-1D was capable of sending 1,000 kg payload to a 200km LEO inclined
at 28.5°, or 350 kg payload to a 900km SSO. The increased payload and accuracy
was achieved by employing a N2O4/UDMH second-stage, and a 3-axis stabilised
solid third-stage.

Propulsion
The first-stage was powered by an YF-2A liquid rocket engine, which
was an improved version of the original YF-2 on the CZ-1. The sea-level thrust
was increased by 81.2 kN, and the sea-level Isp was increased to 2,378 N.s/kg.
On the original design, the second-stage of the CZ-1D was to be powered by
two parallel YF-40 engines burning the N2O4/UDMH propellant.
The propulsion of the third-stage consisted of a FG-36 solid rocket engine
and a DaFY2-1 auxiliary engine. The solid engine used the HTPB solid propellant,
with 645 kg propellant carried onboard. The auxiliary engine, which used the
N2O4/UDMH propellant, was designed to maintain the course of flight during
the gliding stage. The engine consisted of four 1.2 kN/1.6 kN chamber motors
and twelve 25 N chamber motors, located on the third-stage symmetrically.
Airframe
The CZ-1D shared the same (?) airframe design in its first- and second-stage
with the original CZ-1. The diameter of the third-stage was increased from
1.5m to 2.05m. The original cone-shaped inter-stage section between the second-
and third-stage was replaced by a cylinder-shaped design, which also accommodated
the main and auxiliary thrusters of the third-stage.
Guidance
The CZ-1D had adopted a platform-computer inertial guidance system, which
allowed the third-stage of the rocket to be 3-axis stabilised.